Ernesto Aguilar-Palazuelos

Characterization and Optimization of Extrusion Cooking for the Manufacture of Third-Generation Snacks with Winter Squash (Cucurbita moschata D.) Flour

ABSTRACT The aim of this work was to study the effects of barrel temperature (BT, 93.5–140.5°C), feed moisture (FM, 21.3–34.7%), and winter squash flour content (SFC, 0.43–15.6%) on physicochemical properties of microwave-expanded third-generation snack foods obtained by extrusion. Physicochemical properties used for optimization were expansion index (EI), penetration force (PF), specific mechanical energy (SME), and total color difference (ΔE). Response surface methodology was used for the analysis of data. The highest values of EI and lowest values of PF were found at high BT and low FM. The lowest values of SME were obtained at high levels of FM throughout the range of BT and SFC, whereas the highest values of ΔE were obtained at high SFC and low FM. Increasing levels of SFC increased ΔE values, whereas EI and SME values decreased. The best processing conditions (EI > 6.0, PF < 9.5 N, SME < 172 kJ/kg, and ΔE < 18) were found in the range of BT, 122–141°C; FM, 24.7–29.5%; and SFC, 0–10.9%. Under optimal...

Effect of extrusion conditions on physicochemical characteristics and anthocyanin content of blue corn third-generation snacks

The aim of this study was to evaluate the effect of barrel temperature (BT, 98.8–141.2°C) and feed moisture (FM, 19.93–34.07%) as independent factors on physicochemical characteristics of microwave-expanded extruded third-generation (3G) snacks obtained from blue corn and corn starch. Single-screw laboratory extruder and a central, composite, rotatable experimental design were used. Both independent factors showed significance (p ≤ 0.01) on most of the analyzed responses. The mathematical models showed values of R2Adj ≥ 0.76 and p of F(model) ≤ 0.001. The optimum area of the extrusion process ranged from 120°C to 126°C for BT and from 23.8% to 25.2% for FM. In optimal conditions, the product showed an expansion index of 4.8, a penetration force of 12.42 N, a specific mechanical energy of 169.08 kJ/kg, and 71.09 mg of total anthocyanin content/kg. The developed 3G snack presented high-quality physicochemical characteristics, with the potential health benefits derived from nutraceutical characteristics (dietary fiber and anthocyanins) of the whole blue corn used.

Physicochemical Evaluation and Optimization of Enriched Expanded Pellets with Milk Protein Concentrate

ABSTRACT The objective of this work was to study the effect of addition of milk protein concentrate (MPC, 0–10%) and feed moisture (FM, 20–30%) in a blend of corn starch (CS, 80%) and quality protein maize (QPM, 20%) on different physicochemical characteristics of third-generation (3G) snack foods using extrusion technology. A laboratory single-extruder with a 3:1 compression ratio, a rectangular die, and a central composite nonroutable model with two variables were used. The physicochemical characteristics evaluated were expansion index (EI), bulk density (BD), penetration force (PF), and color parameters L*a*b*. EI decreased with the increase of MPC and FM, whereas BD and color parameters (a* and b*) increased; PF showed a minimum point (MPC = 5% and FM = 25%). EI, BD, and PF were selected for the optimization process in an area of superposition of 1.5–4.1% of MPC and 20.0–24.1% of FM. A validation of the optimal area was performed on samples with average values of 4.64 (±0.28) for EI, 141.02 (±7.29) kg...

Elaboration of functional snack foods using raw materials rich in carotenoids and dietary fiber: effects of extrusion processing

This research studied the effect of extrusion temperature (ET, 93.45–140.55°C), moisture content (MC, 21.27–34.73%), and the winter squash flour content (WSF, 0.43–15.57%) on physicochemical characteristics and content of bioactive compounds of third-generation (3G) snack foods expanded by microwave heating. The ingredients used for their elaboration were corn starch, whole-grain yellow corn and winter squash flours. A single-screw extruder was employed, and the response surface methodology was applied. The lowest bulk density and the highest water solubility index (WSI) and water absorption index, occurred at high ET with low MC. The highest values of total carotenoids and dietary fiber (total and soluble) were obtained at high WSF and ET. Furthermore, when the WSF was increased, the color L* value diminished, whereas b* value and WSI increased. These results suggest that it is possible to elaborate 3G snack foods with acceptable physicochemical characteristics and excellent bioactive compounds content, improving their potential health benefits.

Physicochemical and Microstructural Characterization of Corn Starch Edible Films Obtained by a Combination of Extrusion Technology and Casting Technique

Starch edible films (EFs) have been widely studied due to their potential in food preservation; however, their application is limited because of their poor mechanical and barrier properties. Because of that, the aim of this work was to use the extrusion technology (Ex T) as a pretreatment of casting technique to change the starch structure in order to obtain EFs with improved physicochemical properties. To this, corn starch and a mixture of plasticizers (sorbitol and glycerol, in different ratios) were processed in a twin screw extruder to generate the starch modification and subsequently casting technique was used for EFs formation. The best conditions of the Ex T and plasticizers concentration were obtained using response surface methodology. All the response variables evaluated, were affected significatively by the Plasticizers Ratio (Sorbitol:Glycerol) (PR (S:G)) and Extrusion Temperature (ET), while the Screw Speed (SS) did not show significant effect on any of these variables. The optimization study showed that the appropriate conditions to obtain EFs with the best mechanical and barrier properties were ET = 89 °C, SS = 66 rpm and PR (S:G) = 79.7:20.3. Once the best conditions were obtained, the optimal treatment was characterized according to its microstructural properties (X-ray diffraction, Scanning Electron Microscopy and Atomic Force Microscopy) to determine the damage caused in the starch during Ex T and casting technique. In conclusion, with the combination of Ex T and casting technique were obtained EFs with greater breaking strength and deformation, as well as lower water vapor permeability than those reported in the literature.

Effect of extrusion on the carotenoid content, physical and sensory properties of snacks added with bagasse of naranjita fruit: optimization process

ABSTRACT Extruded third-generation snack foods (TGS) can be produced adding materials rich in bioactive compounds, such as the bagasse of naranjita fruit (Citrus mitis B.). The aim of this work was to study the effect of extrusion temperature (ET; 89.8–140.2°C), moisture content (MC; 21.10–32.89%) and dehydrated naranjita bagasse (DNB) content (1.12–11.88%) on TGS properties, such as, carotenoids content, physical and sensory characteristics. For data analysis, response surface methodology was used. The highest expansion index and the lowest penetration force were presented at high ET and low MC, whereas the highest carotenoids content and ΔE were presented at high DNB. Also, the highest sensory acceptability was presented combining high ET and MC, and low DNB. The optimal processing conditions were ET = 125°C, MC = 23% and DNB = 8.03%. TGS with acceptable physical and sensory properties, in addition to important carotenoid levels, were obtained.

Microstructure of an Extruded Third-Generation Snack Made from a Whole Blue Corn and Corn Starch Mixture

Blue corn is a potential material for expanded snack production. Whole blue corn meal was mixed with corn starch and processed by extrusion to produce a third-generation snack. Optimum extrusion conditions were calculated with the response surface methodology using expansion index (EI), penetration force (PF), specific mechanical energy (SME) and total anthocyanins content (TAC). Optimum conditions (zone 1, 67°C; cooking zone, 123°C; zone 3, 75°C; feed moisture, 24.6%) were used to extrude the mixture in a single-screw extruder, and EI,PF,SME and TAC of the expanded pellet were compared against predicted optimum values. Starch structural changes in pellets and expanded were analyzed with DSC, viscosity profiles, x-ray diffraction and SEM. Extruded pellet did not differ (p>0.05) from the predicted. However, TAC was lower (p<0.05) in the expanded pellet. Structural analyses showed damage starch granular structure during extrusion and pellet expansion. Blue corn is a promising material for production of third- generation snacks.

Effect of extrusion cooking on the antioxidant activity of extruded half product snacks made of yellow corn and pumpkin flours

Abstract The effect of the extrusion on the antioxidant activity of extruded half product snacks made of pumpkin and corn flour blends was evaluated. Cehualca pumpkin and yellow corn flours were used. Pumpkin (0.5 to 15.6 %) and yellow corn flours were mixed and then extruded at a temperature range of 93.5–140.5°C. The total phenolic content (TPC) was determined by Folin-Ciocalteu method. The Phenolic acid profile was obtained by HPLC analysis. The antioxidant capacity was measured using DPPH*, deoxyribose, and LDL oxidation inhibition assays. A central composite rotatable design was applied. The highest value of TPC was observed at high extrusion temperature and low pumpkin levels, and at low temperature and high level of pumpkin flour concentration. The highest DPPH scavenging activity was obtained at higher content of yellow corn flour. The best response to OH* scavenging was observed at higher extrusion temperature and lower content of pumpkin.

Blue corn (Zea mays L.) with added orange (Citrus sinensis) fruit bagasse: novel ingredients for extruded snacks

Physicochemical and structural analyses were done of extruded snacks produced with two types of blue corn (hard and soft endosperm) combined with orange bagasse. Chemical composition, expansion index (EI), penetration force, water absorption index, and water solubility index values were calculated for all treatments. They were also analyzed with scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Addition of bagasse increased crude fiber content and hardness in the extrudates. It also lowered the EI, resulting in harder products with higher numbers of pores per area but of smaller sizes than in the extrudates without bagasse. Both the X-ray diffraction patterns and infrared spectra showed the starch to lose its semicrystalline structure due to mechanical shearing and high temperature. Orange bagasse was successfully incorporated into extrudated snacks made with blue corn of different endosperm hardnesses. Blue corn is a viable base for extruded snacks, and orange bagasse is a potential source of low cost, natural source fiber.

Physicochemical and sensory characterization of an extruded product from blue maize meal and orange bagasse using the response surface methodology

ABSTRACT The mixtures of blue cornmeal and orange bagasse were processed in a single screw laboratory extruder. We used an experimental design, central composite rotatable, where the factors were as follows: extruder die temperature (153–187°C), feed moisture (146.4–213.6 g/kg), and orange bagasse concentration (32.7–167.3 g/kg). The results were analyzed by surface methodology response to evaluate the effect of these variables on the expansion index, bulk density, penetration force, specific mechanical energy, water absorption, and water solubility index. All independent variables had an effect on the evaluated responses (p ≤ 0.05). The highest expansion index was obtained at a feed moisture content of 146.4 g/kg, orange bagasse (100 g/kg), and 170°C at the exit die. The use of blue maize and orange bagasse can be an alternative to increase the added value of these two raw materials, and to improve the nutritional quality of extruded products ready to eat.